a new Genus of Foraminifera, 339 



The Foraminifera brought under notice in the foregoing 

 memoir are in a high degree interesting from certain peculiari- 

 ties of structure not hitherto recognized in members of the 

 group to which they belong. It is necessary, however, in the 

 first place to notice one or two errors in the description of the 

 genus ; and this I am enabled to do (through the courtesy of 

 Professor Seguenza) from observations made upon specimens 

 collected in the Sicilian localities alluded to in the text. 



That we have in these beautiful little shells from the Miocene 

 Clays representatives of a new subtypical form of Nodosarian 

 Foraminifera, no one will doubt ; but the characters assigned 

 to them would indicate, if correct, not merely generic or sub- 

 generic peculiarities, but rather a plan of growth entirely new 

 to the order. The most important of these is indicated by the 

 statement that there is no communication between the interior 

 of one chamber and that of the succeeding one. This is proba- 

 bly intended to mean intercommunication in the ordinary 

 way by a central orifice, though no qualification is made of 

 the broad general statement. Were such a supposition verified, 

 it would necessitate the conclusion either that the animal 

 vacated the smaller chambers as succeeding larger ones were 

 formed, or that the minute foramina existing in the shell- 

 wall were sufficient for the exercise of its functional require- 

 ments so far as concerned the intercommmiication of the sar- 

 code-segments — suppositions equally without parallel in the 

 economy of species whose shell-structure has been well made 

 out. The difficulty of accepting the relation of parts indicated 

 in the sectional diagram accompanying the original paper led 

 to the observations of which I now give the results. 



The normal mode of growth amongst the straight Nodosa- 

 rince consists in the formation of a straight line of sarcode- 

 segments united by naiTOw stolons. Each new chamber-wall 

 is produced by the deposit of a calcareous test on a lobe of 

 sarcode issuing from the terminal aperture of the last-formed 

 chamber. Hence each stolon represents the interior of what 

 was in its turn the terminal aperture, and its length depends 

 on the character of the orifice.' In some species, in which the 

 mouth does not protrude, the length of the stolon is only as 

 much as the thickness of the shell-wall, whilst in others the 

 chambers are surmounted by a neck nearly equal in length to 

 the main body of a segment. Prof. Seguenza' s figures of E. 

 ellipsoides show a long terminal neck somewhat of the latter 

 description, as indicated by the dotted lines in figs. 1 & 2, 

 PI. XIII. Unfortunately no specimen has come under my 

 notice in this condition ; consequently my remarks are founded 

 on the corresponding structures in the interior of the shell. 



